Hoo, lessee...the best 'culprits', I think, would be those first 2-3 Os Mutantes albums. There's a LOT there that reminds me of Faust, although the Mutants do tend to make things squeeze more handily into song-like forms. Duprat's production is majorly in evidence there, along with a lot of specialized electronic tinkering done specifically for Os Mutantes that gave them things like the 'aw-aw pedal', etc.

Duprat's also around on some of those 1967-68-ish Caetano Veloso releases, which also used Os Mutantes as his backing band for some pretty wild stuff. They were definitely in on the massive fiasco/riot that was the live TV piece "Prohibido Prohibe" (sp.?), which appears on a particularly good Veloso comp on Polygram that encapsulates his pre-Tropicalia thru London exile period stuff.